Intake/Exaust efficency Turbo 4AGE

[merc-blue]

I have 2 streams of convosation for this thread intake and exaust.

Firstly intake.
Im planning on building a "hot budget" 4AGTE,
I dont plan on curring corners but doing things right and spending money where its due.
For example im using a Megasquirt to save money (and i Belive i can do it right with a megasquirt) but getting oversized valves becasue i feel they are needed.
My intake questions are all about flow,
At the moment this is what im thinking, but i may be way off.
Im using a smallport head with work and slightly OS valves, a std throttle body and intake.
The theory behind this setup comes from a few places. firstly the concept of having huge bigport ports and than small valves seems silly to me if the valves are limiting on a small port than isnt there going to be more issue with small valves on bigports.
The Std manifold is pretty tidy inside and the general shaping of the plenum chamber looks find to me, and at a guess the throttle body isnt limiting my flow either,
I was looking at flow benching the whole intake system as it builts up. eg with valves at massive lift (or not pressent) than with valves at cam range of lift. then with the intake on and finaly with TB on.
Is this all unnesscary, has this research been done before?

Next is exaust.
I was talking to a mate who was raving on about ceramic coating exaust ports and nothing else. i was planning on doing piston crowns exasut ports exaust valves and possibly the manifold and exaust side of the turbo.
Is cermaic coating worth the money it cost if doing it "right"
I am pretty anal about ding things the correct way,
But my lack of turbo engine build knowlage makes me often look like a goose.

Whats worth while in building a FI engine properly, i have the bottom end all sorted as there isnt much different than a NA just use some stronger parts and i was happy to trust the blokes who did the machining work on what they thought was suitable..

From the piston skirt up though Im quite a noob

[Cameron_Datto]

WHO are you getting to fit the oversize seats to the Head ?

[merc-blue]

havnt decided yet,
I have been tempted to get the whole head done by the blokes who do the rest of our work,
While most of it is V8 stuff there is no denying they do good work and understnad what they are doing.
I can think of about 100 places in VIC alone that COULD do it.
Its a matter of finding one who A will do it well and B will do it at a fair price.

At the moment im liking motor improvements becasue i know they are good and do a decent job

Also was talking about the valve/piston crown and if offset grinding for the OS seat was worth while, but that wont be happening

[Talasas]

From my experience and findings, even the standard Smallport head (and intake) is quite capable of decent power, anything you change (read: replace with better performing part) in it will simply yield you better results and you can change whatever you feel necessary.

It's only when you start pushing bigger numbers (lets say maybe 350+ hp) that you might need to tinker to get better gains.

My advice would be to have a properly set up head (neat and clean valve clearances) and if you want cams, go for some lift. If you feel like spending more money, fork out for the shimless/shim-under-bucket conversion, good valve springs and just a rebuild on the head.

[turbo4agte]

I like the fact that you want to do it right, but there are some things that you'll chase after and realize you wasted your time and money and they were overkill for your setup, and did nothing but actually decrease the reliability or longevity of your engine. It really starts on your power goals, and how far your really want to go with it.

Just to give you an idea of where Im going, I know one guy who built a high compression Honda B18C5 that was meant to be street driven and ocassionally tracked, but he used some really strong forged pistons that I think were 2618 alloy steel. This is made only for professional racers but he thought, ohh the stronger, the less blowby I'll get and better compression. Well those pistons dont expand at all like a normal piston, so when they are cold, they scratch up your cylinder walls more than usual. So its like the opposite when daily driven. He of course never took special precautions to warm up the engine like proffesionals, and his compression went down pretty quick. End of story he rebuilt the engine a year later.

[merc-blue]

I understand alot about engines just not FI specific.

While I appreciate your concern, i dont think i am risking my engines longeverty with any of my sugested performance modifacations.
The bottom end cosnsists of OEM pistons Spool Conrods. a "prepared" crank, but im confident that they will all perform flawlessly and last me for a good time..

What im trying to eliminate is the easy "if you had just ceramic coated you pistons tops (cost under 200 bux) you would have seen a few HP increase" that means i have to strain the engine less to get the same output.
I admit the engine will get a 8k limiter which ist low but i certainly dont want to have to be using it

[rms]

some really strong forged pistons that I think were 2618 alloy steel.

Don't know of any steel with that designation !!!!! Steel pistons ??????

A bit of technical knowledge would go a long way.

[turbo4agte]

Forged aluminum, my mistake. And yes they do sell that alloy, it barely has silicon if any.

Good luck with the build. I dont see how ceramic coating the pistons would help that much, but whatever. I dont know it all. I've read that standard 4032 forged aluminum does a good enough job at retarding detonation. Ceramic might be overkill, I dont know. Just do some mroe research on proffesional racer forums.